Adolescents who enter community-based residential treatment have serious alcohol and other drug use problems and are at high risk of relapse in the first 90 days after their discharge. Typically, only about a third of these adolescents get any aftercare treatment and 50%-70% relapse during this period. The Assertive Aftercare Protocol (AAP) combines adolescent community reinforcement approach procedures with case management during home visits for three months after discharge. While this aftercare approach showed promise in the original experiment (the first aftercare experiment published on adolescents), it is hypothesized that using contingency management (CM) procedures to reinforce adolescents when they engage in pro-social activities and abstain from alcohol and other drugs can strengthen it. The proposed study will use a randomized 2 x 2 factorial design to evaluate the impact of enhancing usual aftercare (UA) with AAP, CM, both or neither in the three months after treatment. The specific aims are to evaluate the main effects and interaction of these enhancements in terms of both intermediate outcomes (more aftercare participation, better recovery environment, and more pro-social activities) and longer-term substance use outcomes and related problems. Approximately 324 adolescents from two sites will be interviewed at their admission to residential treatment and at 3, 6, 9, and 12 months post discharge. At residential discharge, all study participants will be referred to UA, a quarter of the participants will be randomly assigned to UA only, a quarter will be randomly assigned to AAP, a quarter will be randomly assigned to CM, and a quarter will be randomly assigned to AAP+CM. The core data sources include: service contact logs, intake and follow-up interviews using the Global Appraisal of Individual Needs (GAIN), and additional measures related to family environment, peer environment, involvement in pro-social activities, satisfaction with adolescent life areas, and involvement in aftercare. Adolescent reports at intake and three months post discharge will be validated by comparison to parent report and urine tests for marijuana and cocaine. It is anticipated that the AAP plus CM condition will result in outcomes superior to the other conditions and be more likely to contribute to longer-term benefits to clients and their families.